Frequencies for first 10,000 rows of comstat3 variable in namcs2009 dataset :

composition status |
              code |      Freq.     Percent        Cum.
-------------------+-----------------------------------
single entity drug |      3,457       34.57       34.57
  combination drug |        494        4.94       39.51
      undetermined |         57        0.57       40.08
                 . |      5,992       59.92      100.00
-------------------+-----------------------------------
             Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 28 Mar 2016